A pro-Russian youngster stands in a crowd-control line during a rally in Lenin Square in Donetsk, Ukraine, on May 18. / Vadim Ghirda, AP

by Portia Walker, Special for USA TODAY

by Portia Walker, Special for USA TODAY

DONETSK, Ukraine - Government supporters in eastern Ukraine urged people Wednesday to vote in a presidential election they hope will blunt an attempt by pro-Russian separatists to win independence.

Among the backers of a unified Ukraine is the country's richest man, Rinat Akhmetov, an industrial magnate worth more than $12 billion who has organized his employees into patrols to take back the port city of Mariupol, which had been held by separatists.

Since Tuesday he has urged his workers throughout the Donbass region of eastern Ukraine to protest every day at noon for a unified Ukraine. Many Ukrainians fear they are being picked apart by Russia, which has taken over the province of Crimea.

At noon Wednesday, a siren went off at the headquarters of Akhmetov's flagship office, a sleek 20-story glass and steel tower built more in the style of Wall Street than eastern Ukraine where he runs his empire of coal mines, factories and industrial plants.

White-collar workers piled out into Lenin Square, a large space in the center of the city, to join a small pro-Ukrainian protest. Passing cars beeped their horns.

The protest was disrupted by a group of pro-Russian separatists. When two young women in a car unfurled a Ukrainian flag, a pair of separatists, one with a metal club and the other with a pickax, chased them. The women sped off in their car.

Other separatists used a crane to try to reach the top of a monument to World War II in the center of the square, where a Ukrainian flag flew. After a number of attempts, they succeeded in hanging the flag of the self-proclaimed Donetsk People's Republic next to it.

A handful of police tried to control the crowd as traffic got jammed.

"If people are trying to stop cars and stop traffic, it's not OK", said Lev, 35, who was alarmed about events in the region and asked that his last name not be used because he was worried for his safety.

"We understand the risk of separation. It could be really harmful and dangerous for the country," he said.

Pro-Russian separatists took over government buildings here in April and declared independence after a referendum May 11 that was condemned by Kiev and Western powers. Ukrainians complain that their country is being divided against their will and that they're unable to publicly express their support for unified nation.

"You're in your country, and you can't show your flag," said Elena Dimitrova, who works in one of Akhmetov's companies. "If you are a patriot, they say that you are a fascist."

A few blocks away from the demonstration was the General Administration building, which serves as a headquarters for the pro-Russian separatist movement in the city. The building is surrounded by barricades made from torn-up paving stones topped with coils of barbed wire.

In recent weeks, the crowds have thinned and garbage has piled around the building, contrasting with the rest of the city's elegant buildings, designer stores and wide tree-lined boulevards.

The separatists are under fire in the town of Slovyansk, which has seen some of the worst fighting in the conflict. Tuesday, the city's self-appointed mayor, Vyachislav Ponomaryov, was accosted by a 200-strong crowd who complained about the violence in the city.